Elevator door operator



Aug. 27, 19 57 A. E. RAQUE ELEVATOR- DOOR OPERATOR e Shee tsSheet 1Filed May 25, 1955.

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4271/02 5 PQQUE HTTOR/VEY ELEVATOR DOOR OPERATOR Arthur E. Raqu,Demarest, N. J., assignor to Watson Elevator Company, Inc., New York, N.Y., a corporation of New York Application May 23, 1955, Serial No.510,173

14 Claims. ((Zl. 268-51) My invention relates to an elevator dooroperator and more particularly to an improved elevator door operator forcontrolling the opening and closing movements of an elevator doorwhereby the door will approach its limit positions at comparatively slowspeeds.

It is desirable in all elevator cabs, and especially desirable in thecase of cabs for automatic elevators, that the last portion of theclosing movement of the elevator door be accomplished at a relativelyslower speed than that of the initial portion of the door closingmovement. This prevents slamming of the elevator door and reduces thepossibility of injury to persons using the elevator or damage to thedoor or the door operator parts. It is, moreover, desirable that thelast part of the opening movement of the door be accomplished at arelatively slower speed than is the initial movement of the door inopening. This prevents jarring of'the door at the open limit position.In most of the elevators of the prior art, the power to the elevatordoor drive is shut oif at a point just short of the open limit position,and the door is permitted to coast to a stop, with the result that thedoor and the door operator parts are jarred to a stop. In my Patent No.2,572,196, dated October 23, 1951, I have disclosed an elevator dooroperating mechanism which provides a relatively slower speed for thefinal portion of the movement of the door to its open limit position andfor the final portion of the movement of the door to its closed limitposition. I have now invented an elevator door operator which representsan improvement on the construction disclosed in the said patent. Myimproved elevator door provides a smooth and silent transmission ofpower from the prime mover to the door. It employs no gears for speedchange and includes no chain drive which becomes noisy when it wearsafter extended use. My operator has a belt and pulley drive and speedchange system which is quiet in operation and will remain so for yearsof constant use. My improved door operator provides the same torque atboth high and low speeds. This torque is sufficient to operate both theelevator car doors and the hoistway doors. My improved elevator dooroperator is provided with a belt nited States Patent drive in which alarge portion of the drive belt is in contact with the belt drivepulleys whereby frictional contact is made over almost the entire lengthof the drive belt to reduce slippage. The magnitude of the force exertedcan easily be adjusted by changing belt tension. Myimproved system isflexible in use in that the same assembly may be used for a wide rangeof door travels. The only adjustments which are necessary in variousinstallations are the provision of longer tracks and the adjustment ofthe settings of the limit switches of the assembly. Since the doormoving force depends on friction, the same force will be appliedthroughout the entire door travel. My door operator is quieter inoperation than the door opening mechanisms of the prior art. 7

One object of my invention is to provide an improved elevator dooroperator for driving an elevator door at a relatively slower speedduring the respective terminal portions of its movements than duringcorresponding initial portions of its movements, both on opening andclosing of the door.

A further object of my invention is to provide an improved elevator dooroperator which delivers a torque sufficient to operate both the elevatorcar doors and the elevator shaft doors.

Another object of my invention is to provide an improved elevator dooroperator having a belt'drive in which a large portion of the length ofthe drive belt is in contact with the drive pulleys.

A still further object of my invention is to provide an elevator dooroperator which is flexible in application so that the same assembly maybe used for a wide range of amplitudes of door motion with few and minoradjustments.

Other and further objects of my invention will appear from the followingdescription.

In general my invention contemplates the provision of an elevator dooroperator including a high-speed drive and a low-speed drive, both ofwhich may be driven from a common prime mover. Any convenient mechanismmay be employed for operating the elevator door from the respectivedrives. For example, I may employ a drum and cable arrangement which isdriven in one direction to open the elevator door and is driven in areverse direction to close the door. I provide means by which the cabledrum drive means may be connected either to the door operator high-speeddrive or the door 3 I operator low-speed drive. When the elevator carcarrying the doors and opener arrives at a floor, a main control relayis actuated to energize the driving prime mover in a direction to openthe elevator door. The driving of the prime mover in this directionurges the connecting means to engage the cable drum drive means with thehigh-speed drive. I provide automatic control means operable by thecable drum for urging the connecting means to connect the slow-speeddrive with the cable drum when the elevator door approaches the fullyopen position. When the door arrives at its opening limit position,'alimit switch interrupts the elevator drive motor circuit to stop themotor. After a predetermined time, operation of a relay reverses thecircuit of the opener drive motor to drive the cable drum in a directionto close the doors. This rotation of the cable drum actuates theconnecting means to connect the fast drive with the cable drum. As thedoor approaches the fully closed position, a limit switch breaks theprime mover circuit and the car is ready to move up or down in itsshaft.

In the accompanying drawings which form part of the instantspecification and which are to be read in conjunction therewith and inwhich like reference numerals are used to indicate like parts in thevarious views:

Figure 1 is a fragmentary front elevation of an elevator car equippedwith my improved door operator, showing the arrangement of the operatorwith relation to the car door.

Figure 2 is a fragmentary front elevation of my improved elevator dooroperator drawn on an enlarged scale.

Figure 3 is a fragmentary top plan of my improved elevator door operatordrawn on an enlarged scale and taken along the line 3-3 of Figure 2.

Figure 4 is a sectional view of my improved elevator door operator drawnonan enlarged scale and taken along the line 44 of Figure 1.

Figure 5 is a sectional view of my improved elevator door operator drawnon a greatly enlarged scale and taken along the line 55 of Figure 3.

Figure 6 is a fragmentary view, drawn on a greatly enlarged scale, ofthe operating arm latch means of my improved elevator door operator.

Figure 7 is a fragmentary perspective view of my improved elevator dooroperator drawn on an enlarged scale.

More particularly referring now to Figures 1 and 4 of the drawings, theelevator cab, indicated generally by the reference character 10, withwhichrny improved ele vator door operator is associated, supports astructural member, indicated generally by the reference character 12, byany convenient means adjacent its top front. 'The' member 12 includes apair of end brackets 14'and '16 which support a top angle iron 18' and abottom angle iron 20. The lower angle iron 20 supports a pairof guiderails 22 and 24. The guide rails 22 and 24 are held to the dependingflange of the angle iron 20 by means of bolts 26 and are maintained inspaced relationship by spacers 28 and 30 carried on the shanks. of. thebolts 26. doors which I shall term respectively a fast door 32 and aslow door 34. The fast door 32 is supported from the guide rail 22 bymeans of a pair of hanger assemblies, indicated generally, respectively,by the ref erence characters 36 and 38. Each of the assemblies 36 and 38includes a housing 40 in which a roller 42 is pivotally mounted on ashaft 44. The arrangement is such that the roller 42 of each of thehanger assemblies movably rests on the rail 22. Each of the housings 40is secured to the door 32 by means of a pair of threaded studs 46extending into the lower flange of the housing and secured therein bynuts 48. bracket 50 by means of nuts 54. Bracket 50 may be attached tothe top of the elevator door by any convenient means, such as bolts 52.The respective assemblies 36 and 38 maybe secured to each other by astructural member 56 extending between the housings 40 and securedthereto by means such as machine screws 58. It will be appreciated thatthe hanger assemblies 36 and 38 provide a means by which the fast door32 is suspended from rail 22 for movement therealong.

In order to support the slow door, I provide a pair of hangerassemblies, indicated generally, respectively, by the referencecharacters 60 and 62. Hanger assemblies 60 and 62 are in all respectssimilar to the assemblies 36 and 38 and like parts of these assemblieshave been indicated by the same reference characters as were used forthe same parts in the assemblies 36 and- 3'8. The studs 46 of theassemblies 60 and 62 secure the respective hanger assemblies directly tothe top of the slow door through brackets 64 and 66. The respective slowdoor hanger assemblies 60 and 62 are connected by a plate 68 fixed tothe assemblies by means of screws 70. As can be seen by reference toFigure 1, the plate .68 extends to the right beyond the assembly 36associated with the fast door 32.

Referring now to Figures 1, 4 and 5, a drive drum, indicated generallyby the reference character 72, is retained on a shaft 74 by"means of awasher 76 held to the shaft 74 by a bolt 78 threaded into a recess 80 inthe shaft end. A key 82 provides a means by which the shaft 74 iscoupled with the drum 72 for rotation therewith. Shaft 74 is rotatablysupported in a bearing 84 retained in a recess in one arm 86 of aU-shaped bracket, indicated generally by the reference character 88, bymeans of a retaining ring 90 secured to the arm 86 by machine screws 92.The bracket 88 is fastened by bolts 94 to the horizontal flange of theangle iron 18 of the structural member 12. Bracket 88 includes a secondarm 96. Drum 72 is arranged, when driven, to drive the door opener cable98 which is passed around the grooved portion 100 of the drum 72. Theportion of cable 98 extending to the left from drum 72, as viewed inFigure 1, passes around a first idler pulley 102 rotatably mounted on apin 104 carried by a U-shaped idler bracket 106 fixed to the bracket 14by means of a bolt-108. After passing aroundsheave 102, cable 98 passesaround a pul- The elevator door assembly includes two.

Studs 46 are secured to a ley 110 pivotally mounted on a shaft 112 fixedby any convenient means to the fast door pulley support plate 56. Frompulley 110 cable 98 passes around a pulley 114 pivotally carried by ashaft 116 supported on the slow door pulley support plate 68. Cable 98then extends around a second pulley 118 rotatably mounted on a pin 120carried by the portion of plate 68 which extends ,to the right of slowdoor hanger assembly 62 as viewed in Figure 1. After passing around thepulley 118, cable 98 is secured bya fitting 122 to the bracket 14.

The portion of cable 98 extending to the right from drum 72, as viewedin Figure 1,.passes around an idler sheave 124 rotatably mounted on apin 126 carried by a U-shaped sheave support bracket 128 secured tobracket 16 by a bolt 130. After passing around sheave 124 this portionof cable 98 travels around a pulley 132 rotatably mounted on a pin 134carried by supporting plate 56. From the pulley 132 cable 98 passes to afitting 136 by means of which the cable is secured to the bracket 16.

When drum 72 is driven'in one direction or the other, cable 98 will bedriven to open or to close the elevator doors. Advantageously, thepulley arrangement just described provides such mechanical advantagethat the fast door 32 is driven at twice the speed at which the slowdooris driven. It is to be understood that the arrangethe direction ofrotation of drum 72 is reversed,.the

t doors close.

I provide both a fast and a slow drive for the drum 72.

As can be seen by referenceto Figure 4, drive pulley sup- 'bolts 144.The upper end of bracket 140 supports a motor platform 146 by means ofbolts 148. Platform 146 carries a drive motor 150 having a shaft 152 towhich a pulley- 154 is fixed for rotation therewith.

As can be seen by referenceto Figures 1, 2, 4 and 7, pulley,154 drives abelt 156 which drives a sheave 158. Sheave 158 is fixed on an extendedhub portion of a slow speed pulley 174 which is rotatably mounted by abushing 162 or the like on a shaft .160 which is fixedly supportedinbracket 140. It will be appreciated that when sheave 158 is driven,the slow speed pulley 174 alsois driven, though with a lower peripheralspeed. Belt 156 also drives a second pulley 164 rotatably supported by abushing 168, or theh'ke, on a shaft 166 carried by bracket 140. Drum 72includes a sheave 170 adapted to be driven by a belt 172. Belt 172 mayalternately be engaged, by means 'to be described hereinafter, with theslow speed pulley 174- or with a high speed pulley 176. Pulley 176 isformed integrally with the pulley 164 and is likewise rotatablysupported on shaft 166 by bushing 168. When the 'belt 172 is engagedwith the pulley 176, drum 72 is driven at a high speed. When thezbelt172 is engaged with the pulley 174 on shaft 160, the belt will be drivenat a low speed. The speed ratio between pulleys 174 and'176 isdetermined by the relative diameters of the respective sheave 158 andpulley 164. Since both these pulleys are driven by the same belt 156,the

linear speed atthe periphery of each of the sheave 158 and pulley 164will be the same. However, since sheave 158 has a diameter which is muchlarger than-the diameter of pulley 164, pulley 174 will bedriven at acorrespondingly slower speed than will the pulley 176.

Referring now to Figures "1, 2 and 7, in order to engage the belt 172with either the slow pulley 174 or the fast pulley 176, I.provide abeltshifting arm 178 fixed on a shaft 180 rotatably mounted in a bushing1.82 carrie y bracket 140. Arm 178 rotatably carries a pulley'184 on oneend thereof by means of a pin 186. It will readily be appreciated thatwhen arm 178 is in the up position as viewed in Figure 7, pulley 184urges belt 172 to a position where it is engaged with the fast drivepulley 176. The limit of this up position is determined by a stop 188secured to the bracket 140 in a position to engage the end of arm 178remote from pulley 184. The down position of pulley 184 is determined bya second stop 190 fixed by any convenient means to the bracket 140. Whenpulley 184 occupies its down position, indicated in broken lines inFigure 2, belt 172 engages the slow drive pulley 174. It will readily beunderstood that when belt 172 is engaged with pulley 176, it does notengage pulley 174. Similarly, when belt 172 engages pulley 174, it isdisengaged from pulley 176. Owing to the inherent elasticity of belt172, arm 178 has a toggle action in moving between its fast and slowdrive positions which tends to resist a shifting of the arm 178.

When the elevator cab arrives at a floor, a switch (not shown since itis known to the art) on the main motor control is operated to energizemotor 150 to drive shaft 152 in a direction to open the doors. In orderto open the doors shaft 152, and thereby shaft 74, are rotated in acounterclockwise direction as viewed in Figures 1 and 2 and in aclockwise direction as viewed in Figure 7. Since belt 156 provides adriving engagement between pulley 154 and the pulleys 158 and 164, thesepulleys will be driven in the same direction as shaft 152. At the timethe elevator c-ab arrives at a floor pulley 184 is in the down or slowdrive position as viewed in Figure 7 wherein the belt 172 engages pulley174. The belt shifter pulley has been left in this position at the endof the preceding operation, as will be explained hereinafter. When shaft152 drives belt 156 in a direction to open the doors, belt 172 is drivenby virtue of its engagement with pulley 174 in a direction to urge thebelt shifting pulley 184 from the down or slow drive position to the upor fast drive position at which the belt 172 engages pulley 176. Whenbelt 172 thus engages pulley 176, the cable 98 is driven in a directionto open doors 32 and 34 with the door 32 traveling at a speed which isgreater than that at which door 34 travels. This faster rate of travelof door 32 is, as has been explained hereinabove, the result of themechanical advantage provided by the door opening pulley system.

Referring now to Figures 6 and 7, my operator includes a latch 192frictionally carried by a second extended portion of the hub of pulley174 on the other side of pulley 174 than that on which sheave 158 ismounted. As will be explained in detail hereinafter, during a portion ofthe closing movement of the door, latch 192 engages a pin 194 to retainpulley 184 in the up or fast drive position against the belt action. Itis desirable, however, that this latch be held out of engagement withthe pin 194 when pulley 184 is the up or fast drive position during theopening of the doors. This is accomplished by virtue of the frictionalengagement of the latch with the hub of the slow pulley 174. As this hubrotates in a clockwise direction as viewed in Figure 7 during theopening of the doors it carries the latch along with it. In order tolimit the movement of the latch in either direction as pulley 174rotates, I fixedly mount a disk 196 carrying a stop pin 198 on the shaft160. As latch 192 is carried along with the hub of pulley 174 in aclockwise direction, a tangential extension 200 on latch 192 engages pin198 to arrest the movement of the latch. When latch 192 is so arrested,the hub of pulley 174 slips with respect to the latch.

As can be seen by reference to Figure l, a bracket 282 secured to plate56 by screws 204 carries a cam roller 266 by means of a pin 208. Whenthe doors are in closed position, roller 206 engages the operating arm210 of a switch 212 carried by angle iron 18. When so eng-aged,operating arm 210 closes the switch through a button 214. As the doorsbegin to open roller 206 releases the arm 210 so that it may be actuatedby a spring 216 to permit the switch 212 to open. This switch 212 is asafety switch which breaks the normal elevator car operating circuit.

It is desirable that the elevator door drive be shifted to a slow driveposition in accordance with my invention as the door approaches itsfully open position in order that the door not be slammed open andpossibly damaged. In order to accomplish this, I provide means forurging arm 178 against the action of the drive belt 172 to a position atwhich belt 172 engages the slow drive pulley 174 and disengages the fastpulley 176. Referring now more particularly to Figure 5, the shaft 74which is rotatably supported in arm 86 of bracket 83 by bearing 84 has afriction disk 218 fixed thereon for rotation therewith by means of a pin220. Rotatably mounted on a bushing 222 on shaft 74 adjacent thefriction disk 218 is an idler member 224. A second friction disk 226 ismounted on shaft 74 for rotation therewith and axial movement therealongby means of a spline or key 228. It will readily be appreciated that ifdisk 226 is urged toward disk 218, the idler 224 will be clamped betweenthe two friction disks so as to be driven with the shaft 74. Alsocarried on shaft 74, by means of key 228 is a screw or worm member,indicated generally by the reference character 230. The end of thismember adjacent the disk 226 is formed with a head 232 having a numberof recesses 234 in its face adjacent disk 226. Springs 236 are disposedwithin the recesses 234 to bear against recess portions 238 which areformed on the disk 226. It will readily be appreciated that if worm 238moves to the right as viewed in Figure 5, springs 236 exert a clampingpressure against idler 224 to clamp that member to disk 218 so that itwill rotate with shaft 74. The head 232 of the worm 230 is connectedwith disk 226 by means of bolts 248 disposed in countersunk bores 242 inhead 232 and screwed into holes 244 in disk 226. Nuts 246 hold the boltsin position with relation to disk 226. As worm 230 moves to the left asviewed in Figure 5, disk 226 is carried away from member 224 by theconnection between head 232 and disk 226 provided by bolts 240. As worm230 moves to the right as viewed in Figure 5, springs 236 urge disk 226into engagement with member 224 to clamp the member between disk 226 anddisk 218. The countersunk bores 242 in head 232 permit relative movementbetween head 232 and disk 226 in the clamping direction to ensure highclamping pressure. An internally threaded cylindrical member 248 isretained in an opening 258 provided in the arm 96 of bracket 88 by meansof retainers 252 secured to arm 96 by bolts 254. The arrangement is suchthat the end of worm 230 remote from head 232 threadably engages theinternal threads of the bore member 248. It will readily be appreciatedthat as shaft 74 turns, worm 230 also turns. By virtue of the engagementof the threads of worm 230 with the internal threads of the member 248,worm 230 will be moved in one direction or the other along the shaft 74depending upon the direction of rotation of shaft 74. The direction ofrotation of shaft 74 during the opening of the doors is-such that worm230 moves from the left in Figure 5 towards the right. The arrangementis such that when the doors approach their fully open position, worm 238has traveled to a position at which springs 236 clamp the member 224between disks 226 and 218. When this occurs, member 224 is clamped torotate with shaft 74 in a clockwise direction as viewed in Figure 7.

As can be seen by reference to Figures 2, 3, 5 and 7, the member 224carries a depending lug 256 to which a fitting 258 is pivotallyconnected by a pin 260. A connecting rod 262 is threaded at one end infitting 258 and at the other end is pivotally connected to a crank 264by means of a fitting 266 and a pin 268. The end of crank 264 remotefrom pin 268 is fixed on shaft for rotation therewith. Referring now toFigure 7, when '7 shaft 74 is driven in a clockwise direction during'the opening; of the door, the clamped member 224 is also driven in aclockwise direction to push connecting rod 262 to the left as viewed inthe figure and to rotate crank 264 and shaft 180 in a counterclockwisedirection. Since arm 178' is fixed on shaft 180 for rotation therewith,the rotation of shaft 180 under this action of member 224 rotates arm178 until pulley 184 engages belt 172 with the slow speed pulley 174 anddisengages it from the fast drive pulley 176. This is the broken-lineposition shown in Figure 2. As can beyseen by reference to Figures 3 and7, in order to interrupt the circuit of the operator drive motor 150when the elevator door has arrived at the fully open position, I providean opening limit switch 270 which may conveniently be carried by abracket 272 supported on the iron 18. A threaded rod 274, supportedbetween arms 86 and 96 of bracket 88 and secured thereto by nuts 276,pivotally supports the actuating member 278 associated with switch 270.A split collar 280 clamped to the head 232 of worm 230 adjacent disk 226by means of a nut 282 carries cam roller 284 on a pin 286. Thearrangement is such that when the doors have arrived at their fully openposition, worm 230 has moved to a position at which roller 284 engagesthe actuator 278 to operate mercury switch 270 to interrupt the elevatordoor opening drive circuit.

Inthe event my door operator is employed on an automatic elevator, atime delay relay (not shown) reverses the circuit of motor 150 after apredetermined time interval to drive cable 98 in a direction to closethe doors. When belt 156 is driven'in a direction to close the doors,itdrives the slow drive pulley 174 in a counterclockwise direction asviewed in Figure 7; that is, a clockwise direction as viewed in Figures1 and 2. The pulley 176, the pulley 184, and the shaft 74 all will bedriven in the same direction as pulley 174; When the pulleys are sodriven, the action of belt 172 tends to pull arm 178 down to the slowdrive position, as viewed in the figures. Since the arm has been left inthis position at the end of the door opening, the belt action tends toretain the arm in this position. It will be remembered, how ever, thatthe member 224 was left clamped between friction disks 226 and 218 atthe end of the door opening operation. Consequently, when the directionof drive is reversed to close the doors, member 224 moves arm 178against the action of the belt 172 to a position where belt 172 engagesthe fast drive pulley 176. I provide means for preventing the movementof arm 178 to the slow drive position when member 224 is unclamped asworm 230 moves to the left as the doors close. Latch 192 which wasfrictionally held by the hub of pulley 174 out of engagement with pin194 during the opening of the doors is frictionally urged in theopposite direction by the hub of pulley 174 when the motor reverses sothat it engages pin 194 to hold arm 178 in the fast drive positionagainst the action of the belt 172. This movement of the latch 192 islimited by the engagement of pin 198 with a second tangential extension288 formed on the latch. From the foregoing explanation it will be seenthat the initial movement of the doors in closing is under the influenceof the fast drive. As has been explained hereinabove, it is desirablethat the terminal portion of the movement of the doors be under theaction of the slow drive.

I provide means for releasing the latch 192 as the doors approach thefully closed position to permit belt 172 to move roller 184 to the slowdrive position where the belt 172 is engaged withpulley 174 anddisengaged from pulley 176. As can be seen by reference to Figures 3, 6and 7, I mount a crank 290 on a shaft 292 for rotation therewith. Shaft292 is rotatably supported in a bushing carried in bracket 140. Crank290 carries a pin 294 in a position to engage the extension 288 of latch192. As can be seen by reference to Figure 7, if shaft 292 is rotated ina counterclockwise direction, pin 294 engages extension 288 to movelatch 192 on the hub of pulley 1714in'a directiontorelease pin 194 andpermit the belt action to bring pulley 184 to the slow drive positionwhere belt" 172- engages the slow drive pulley 174. In ordertoaecornplish thismovement of shaft 292 l mount a crank 296 on shaft 292for rotation therewith. Aconnecting rod 298-is pivotally connected by apin 300 at one end to crank 296'. 'The other end of rod 29 8 isconnected by a pin 302 to a crank 304. Crank 304 is carried by: a sleeve306 for rotation therewith. Sleeve 306, in turn, is rotatably mounted ona rod or stationary shaft 308 extending between the sides 86 and 96 ofthe bracket 88. Nuts 310 retain rod 308 in the sides 86 and 96 of thebracket 88. It will readily be appreciated that when sleeve 306 isturned in a counterclockwise direction as viewed in Figure 7, shaft 292also will be turned in a counterclockwise direction. I provide anoperating means for turning sleeve 306 in a counterclockwise directionat the proper point in the closing movement of the doors .to connect thedoor drive with the slow drive pulley.

This mechanism includes a second crank 312 mounted on sleeve 306 forrotation therewith. An actuating lever 314 is connected at one end tocrank 312 by a pin 316. The other end of lever 314 is pivotally carriedby a rod 318 fixed between the sides 86 and 96 of bracket 88 by nuts320. An adjustable fitting 322 may be employed to position lever 314along the shaft 313. Also, to permit this movement, the crank 312 may beprovided with a hub portion by means of which it is adjustably mountedon sleeve 306. A set screw 324 may be employed properly to positioncrank 312.

Referring now to Figures 3, and 7, in order to actuate the lever 314 tooperate crank 312 at the proper point in the closing movement of thedoors, I provide a cam roller 326 pivotally carried on a pin 328 in asplit collar 330 clamped on the worm 230 by means of a bolt 332. It willbe remembered that as the doors close worm 230 travels to the left, asviewedv in Figure 5. When the worm travels a predetermined distance,,cam roller 326 engages a bearing portion 334 carried by lever 314. Whenthis occurs lever 314 is moved downwardly as viewed in Figure 7 to pivotin a counterclockwise direction about shaft 318. This action operatescrank 312. to pivot sleeve 306 in a counterclockwise direction. aboutthe shaft 303. As a result of this movement of the sleeve, connectingrod 298 is moved generally to the right: as viewed in Figure 7 to pivotshaft 292 in a counterclockwise direction. As the action of lever 314 Iadjustably mount an eccentric step 336 on a shaft 338 fixed between thesides 86 and 96 of bracket 88 by nuts 340'. It will readily beappreciated that the throw of crank 312 may readily be adjusted bychanging the angular position of stop 336 on shaft 338.

I have also provided a means for returning lever 314 and the associatedassembly to its initial position after it has been engaged and actuatedby cam roller 326. A crank 342 fixed on shaft 292 for rotation therewithis engaged by a spring 344 disposed on a stud or rod 346 fixed in shaft160. It will readily be appreciated that the action of the spring 344urges crank 342 and shaft 292 me clockwise direction as viewed in Figure7 to pull rod 298 to the left as viewed in the figure and to rotatesleeve 306 in a directionto return lever 314 to the up position by theaction of crank 312. The support bracket carries a pin 348 which ispositioned to be engaged by crank 290 to limit the return movement ofthe crank.

A limitswitch 350 carried by brackets 352 is providedforinterruptingnthe circuit to motor when the elevator doors arrive attheir fully closed position. Associated with the switch 350 is anactuating member 354 pivotally carried by rod 274. In order to actuatemember 354 I provide a cam roller 356 pivotally carried by a pin 358 ona split collar 360 clamped on the head 232 of worm 230 by a bolt 362. Asthe doors arrive at their fully closed position and worm 230 and head232 move to the left, roller 356 engages member 354 to actuate switch350 to interrupt the motor drive circuit. When this occurs the doors arefully closed and the elevator is ready to move to the next floor. Itwill be understood that as the doors move to the fully closed positionthe safety switch 212 is closed so that the main motor drive circuit isin a condition to be energized.

In operation, when the elevator car arrives at a floor, the mastercontrol circuit, which is known to the art, operates to energize thedoor drive motor 150. The energization of motor 150 to open the doorsdrives shaft 152 and pulleys 158, 164, 174, 176 and 184 in acounterclockwise direction as viewed in Figures 1 and 2 and in aclockwise direction as viewed in Figure 7. This action results in atravel of worm 230 to the right as viewed in Figure 5. As has beenexplained hereinabove, on the antecedent closing of the doors the pulley184 has been left in the down position at which belt 172 engages theslow drive pulley 174 and worm 230 is in its extreme lefthand positionas viewed in Figure 5. However, the direction of drive of belt 172 uponenergization of drive motor 150 to open the elevator doors is such thatthe belt action pulls pulley 184 to the up position at which belt 172engages the fast drive pulley 176. It is to be understood that therelative disposition of the parts of the assembly is such that arm 178acts as a toggle arm. The inherent elasticity of belt 172 permits thisaction and tends to maintain the arm 178 in a beyond dead centerposition. As belt 172 urges the pulley 184 in one direction or theother, the momentum of the system carries the pulley past dead centerwith respect to shaft 180 so that it travels past dead center to theposition opposite to that from which it has been moved. Accordingly, onopening of the doors the action of belt 172 urges pulley 184 from thedown position as viewed in Figure 7 in which it has been left, to the updrive position at which the belt 172 engages the fast drive pulley 176.When this occurs, both doors 32 and 34 move in an opening directionunder the action of the fast drive. Door 32, however, moves faster thandoes door 34 by virtue of the mechanical advantage provided by the doorpulley drive system. When the doors approach the fully open position,worm 239 has traveled a sufiicient distance to the right as viewed inFigure so that friction member 226 clamps the idler member 224 againstfriction disk 218. By virtue of this action, member 224 is engaged withshaft 74 and is rotated in a direction to push rod 262 to the left asviewed in Figure 7. This action lowers arm 178 to engage belt 172 withthe slow drive pulley 174. The doors 32 and 34 are driven at a slowspeed until cam roller 284 engages member 278 to interrupt the dooropening drive circuit of motor 150. It will be remembered that whenpulley 184 is moved to the fast drive position during the initialportion of the opening movement of the doors, latch 192 is frictionallyheld out of engagement with pin 194 by pulley 174, on the hub of whichlatch 192 is mounted.

After a time delay relay (not shown) operates in a known manner, thedirection of drive of motor 150 is reversed to close the doors. Whenmotor 150 is so energized, shaft 152 and pulleys 158, 164, 174, 176 and184 rotate in a clockwise direction, as viewed in Figures 1 and 2, andin a counterclockwise direction, as viewed in Figure 7. It will beremembered that at the end of the opening movement of the doors, drivepulley 184 was left in the slow drive position at which belt 172 engagedpulley 174, member 224 was left clamped to shaft 74, and worm 230 was inits extreme right-hand position as viewed in Figure 5. As motor isenergized to close the doors, member 224 is driven in a direction tomove pulley 184 against the action of belt 172 to a position at whichthe belt 172 engages the fast drive pulley 176. Since the direction ofrotation of pulley 174 is also reversed, latch 192 is moved to aposition to engage pin 194 to hold pulley 184 in the fast drive positionto which it has been moved. As Worm 230 moves to the left as viewed inFigure 5, as the doors close, cam roller 356 engages lever 314 to pivotsleeve 306 in a direction to move rod 298 to the right as viewed inFigure 7. This action rotates crank 290 in a direction to move latch 192out of engagement with pin 194. The belt action then moves pulley 184 tothe slow drive position at which belt 172 engages pulley 174. Thisoccurs as the doors approach the fully closed position. A short timethereafter, cam roller 356 engages member 354 to actuate switch 350 tointerrupt the door closing circuit of motor 150. This occurs when thedoors arrive at their fully closed position. As the doors close, camroller 206 closes safety switch 212 so that the elevator cab drive motorcircuit may be energized to drive the cab to the next floor.

It will be seen that I have accomplished the objects of my invention. Ihave provided an improved elevator door operator having a slow speedterminal portion for both the opening and closing movements of theelevator doors. My operator delivers suflicient torque to operate boththe cab doors and wall doors if necessary. Slippage in my system isdistributed over almost the entire length of the drive belt. My operatoris extremely flexible in that the same assembly may be used for a Widerange of door travels with only minor adjustments. My operator is notlimited to sliding door type elevators but may be used on elevatorshaving other kinds of doors. My operator is quieter than operators ofthe prior art.

' It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of myclaims. It is further obvious that various changes may be made indetails within the scope of my claims without departing from the spiritof my invention. It is therefore to be understood that my invention isnot to be limited to the specific details shown and described.

Having thus described my invention, what I claim is:

1. A door operator including in combination a door, means mounting saiddoor for movement between an open position and a closed position, firstdrive means for driving said door at a given speed, second drive meansfor driving said door at a speed which is less than said given speed,means for connecting said door alternately with said first drive meansand said second drive means, and control means for actuating saidconnecting means to couple said connecting means with said first drivemeans during the initial portion of movement of said door toward each ofsaid open position and said closed position and for actuating saidconnecting means to couple said connecting means with said second drivemeans during the terminal portion of movement of said door toward eachof said open position and said closed position.

2. A door operator as in claim 1 including a common prime mover andmeans operated by said prime mover for driving said first and saidsecond drive means.

3. A door operator as in claim 1 in which said connecting means includesa belt, means driven by said belt for moving said door, a pulley inengagement with said belt, and means mounting said pulley for movementalternately to engage said belt with the first drive means and to engagesaid belt with the second drive means.

4. A door operator including in combination a door, a belt, means drivenby said belt for moving said door to an open position and to a closedposition, first drive means for driving said belt at a given speed,second drive means for driving said belt at a speed less than said givenspeechbelt shifting means for connecting said belt I1 alternately withsaid first drive meansand with said second drive means, and controlmeans for actuating said belt shifting means to engage said belt withsaid first drive means during the initial portion ofmovement of saiddoor and for actuating said belt shifting means to engage said belt withsaid second drive means during the terminal portion of movement of-saiddoor to either said open or closed positions.

5. A door operator as in claim 4'in which said first and second drivemeans move in one direction to move said door to the open position andin the opposite direction to move said door to said closed position, thedirection of movement of said drive means when said dooris moving tosaid open position being such that said belt urges said belt shiftingmeans to engage said belt with said first drive means, said controlmeans including means for urging ,said belt shifting means to engagesaid belt with said second drive means as said door approaches the openposition.

6. A door operator as in claim 4 in which said first and second drivemeans move in one direction to move said door to the open position andin the opposite direction to move said door to the closed position, thedirection of movement of said drive means when said door is moving tosaid closed position being such that said belt urges the belt shiftingmeans to engage said belt with said second drive means, said controlmeans including means for moving said belt shifting means against theaction of said belt to engage said belt with said first drive means atthe beginning of the movement of said door to a closed position, meansfor retaining said belt shifting means against the action of said beltin a position where said belt engages said first drive means, and meansfor releasing said retaining means as said door approaches said closedposition.

7. A door operator including in combination a door, means mounting saiddoor for movement between an open position and a closed position, adrive belt, means operated by said drive belt for moving said door, afirst drive pulley for driving said belt to move said door at a givenspeed, a second drive pulley for driving said belt to move said door ata speed which is less than said given speed, a belt shifting pulleyengaged with said belt, means mounting said belt shifting pulley toengage said belt alternately with said first drive pulley and with saidsecond drive pulley, and control means for moving said belt shiftingpulley to a position where said belt engages said first drive meansduring the initial portion of the movement of said door and for movingsaid belt shifting pulley to a position where said belt engages saidsecond drive pulley as said door approaches either of its open or closedpositions.

8. A door operator as in claim 7 in which the direction of movement ofsaid drive means when said door moves toward an open position is suchthat said belt shifting pulley is urged to a position where said beltengages said first drive pulley, said belt shifting pulley mountingmeans including a shaft, an arm carried by said shaft for rotationtherewith, said control means including a clutch having a driving memberand a driven member normally disengaged at the beginning of the movementof said door toward the open position, means responsive to the movementof said means connecting said belt to said door for engaging said drivenand said driving members as said door approaches its open position todrive said driven member, a linkage connecting said driven member tosaid belt shifting pulley mounting shaft, the direction of drive of saiddriven member when engaged during the movement of said door to an openposition being such as will move said belt shifting pulley against theaction of said belt'to a position where said belt engages said seconddrive pulley. V g

9. A door operator as in claim 7 in which the direction of movement ofsaid drive means when said door moves toward said closed position issuch that said belt urges said belt shifting pulley to a position wheresaid belt engages said second drive pulley, said belt shifting pulleymounting means including a shaft, an arm carried by said shaft forrotation therewith, said control means including a clutch having adriven member and a driving member carried by said means connecting saidbelt with said door, said driven and said driving members being normallyengaged at the beginning of the movement of said door toward said closedposition, means responsive to the movement of said means connecting saidbelt with said door for disengaging said clutch, a linkage connectingsaid driven member with said shaft, the direction of movement of saidconnectingmeans being such that said driven member urges said shaft inadirection to move said belt shifting pulley to a position where saidbelt engages said first drive pulley before the disengage-i ment of saidclutch, means for retaining said belt shifting pulley support arm in aposition where said belt engages said first drive pulley after saidclutch is disengaged, and

means, actuated by said means responsive to the movement of said meansconnecting said belt with said door for disengaging said retaining meansas said door apprime mover for said first drive pulley and said seconddrive pulley, first means responsive to the movement of said meansconnecting said belt with said door for deenergizing said primemoverwhen said door arrives at an open limit position and second meansresponsive to the movement of said means connecting said belt to saiddoor for de-energizing said prime mover when said door arrives at aclosed position.

ll. A door operator including in combination a door, means for mountingsaid ,door for movement between limit positions, a prime mover, firstmeans driven by said prime moverat a given speed, second means driven bysaid prime mover at a speed which is less than said given speed, doordrive means adapted to be coupled alternately with said first drivenmeans or said second driven means, means connecting said door means tosaid door to move said door toward a limit position, means for couplingsaid door drive means alternately with said first driven means or saidsecond driven means, and means for actuating said coupling means tocouple said door drive means with said first driven means during theinitial portion of the movement of said door toward each one of saidlimit positions and to couple said door drive means with said seconddriven means during the terminal portion of the movement of said doortoward each of said limit positions.

12. A door operator including in combination a door,

, means for mounting said door for movement between open and closedpositions, an endless belt, means driven by said endless belt for movingsaid door toward one of said positions, a first drive sheave for saidendless belt, first drive means for driving said first sheave at a givenperipheral speed, a second drive sheave for said endless belt, seconddrive means for driving said second sheave at a peripheral speed whichis less than said given angular speed, a control pulley for said endlessbelt, means mounting said control pulley for movement alternately to aposition where said endless belt engages said first drive sheave or to aposition where said endless belt engages said second drive sheave andcontrol means for actuating said mounting means to position said belttoengage said firstsheave during the initial portion of movement of saiddoor toward one of said open or closed positions and to actuate saidmounting means to position said belt to engage said second drive sheaveduring the terminal portion of movement of said door toward the other ofsaid positions. V

13. A door operator as in claim 12 in which said mounting means-includesan arm, a shaft, means mounting said arm on said shaft for movementtherewith, the direction of movement of said belt as said door moves tothe open position beingsuch that said'control pulley is urged to sheave,said control means including a clutch responsive to said means driven bysaid endless belt for moving said shaft to move said pulley against theaction of said belt to a position where the belt engages the seconddrive sheave.

14. A door operator as in claim 12 in which said mounting means includesan arm, a shaft, means mounting said arm on said shaft for rotationtherewith, the direction of movement of said belt as said door movestoward the closed position being such that said control pulley is urgedto a position to engage said second drive sheave, a clutch responsive tothe movement of the means driven by the endless belt to urge saidcontrol pulley to position said belt to engage said first drive sheaveat the start of movement of said door toward the closed position, latchmeans for retaining said arm in a position where said control pulleyengages said belt with 1 1 said first drive sheave, and means responsiveto said means driven by the prime mover for releasing said latch meansat a predetermined point in the movement of said door toward the closedposition.

References Cited in the file of this patent UNITED STATES PATENTS676,833 Bitner June 18, 1901 2,432,293 Di Giovanni Dec. 9, 19472,458,402 Myers Ian. 4, 1949 2,526,503 Raque Oct. 17, 1950 2,572,196Raque Oct. 23, 1951 2,598,709 Morris June 3, 1952 2,673,316 Doeg et alMar. 23, 1954 2,700,542 Geyer Jan. 25, 1955 2,715,662 Andrews Aug. 16,1955

